Chemical Reaction Optimization (CRO) algorithm plays an important role to determine optimal parameters of PID controller in which the model of DC motor is used as a plant. Tuning PID controller using the traditional ZieglerNichols (ZN) method usually produces large overshoot and Integral time absoluteerror, Integral absolute error and Integral square error performance indices.Therefore, recently researchers have applied random search approaches such asGenetic algorithm (GA), Particle Swarm Optimization (PSO) and Grey WolfOptimizer (GWO) to find optimal parameters for PID controller. Among modernheuristic algorithms, CRO was introduced in 2010, it combined advantage featuresof both GA and Simulated Annealing (SA) to find global minimum in search space.In this paper, we describe the application of CRO algorithm to search optimalparameters for PID controller because CRO combines both features of local andglobal searching techniques to increase the chance of finding global solution. Thecomparison of tuning PID controller by CRO and traditional Ziegler-Nicholsmethod is also presented. The simulated results show the advantages of tuning PIDusing CRO compared to traditional methods in terms of performance indices andtransient responses